US6607552B1 - Rolling socks - Google Patents

Abstract

A rolling retractable stent retaining sleeve for retaining a stent on a balloon catheter comprising a tubular sleeve. The tubular sleeve having a double walled construction which comprises an first layer and an second layer. A first portion of the first layer is constructed and arranged to engage at least a portion of a catheter. A second portion of the first layer is constructed and arranged to overlie an end of a stent prior to delivery of the stent. The first layer is everted such that it folds back upon itself to form the second layer. The double walled sleeve constructed and arranged to roll off of the stent during stent delivery.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Not Applicable

BACKGROUND OF THE INVENTION

1. Field Of The Invention

This invention relates to a medical device delivery systems, namely catheter mounted stent delivery systems. More particularly, the present invention is directed to socks or sleeves used to retain a stent on a stent delivery catheter. The present invention provides for one or more stent end retaining sleeves having a double wall construction. The double wall construction allows the sleeve(s) to be readily and completely retracted off the stent ends during a stent delivery procedure while retaining an extremely low profile relative to the catheter. In at least one embodiment of the invention the double wall sleeve(s) may be characterized as a tube folded over upon itself to form a continuous loop, wherein a portion of the folded over tube overlies an end of the stent and a portion of the tube is engaged to the catheter shaft. The tube may be retracted off of the stent in a number of ways. The tube may be constructed to roll, slide, or other wise retract away from the stent when the stent expands during delivery. The sleeve may be used singly or in pairs with either self-expanding or balloon expandable stents. In the case of a self expanding stent, one or more sleeves may be utilized in conjunction with one or more retractable sheaths. The sleeve(s) may be provided in a variety of lengths to provide partial to full stent coverage. Other inventive aspects and embodiments of the present end retaining sleeves will be made apparent below.

2. Description Of The Related Art

Stents and stent delivery assemblies are utilized in a number of medical procedures and situations, and as such their structure and function are well known. A stent is a generally cylindrical prosthesis introduced via a catheter into a lumen of a body vessel in a configuration having a generally reduced diameter and then expanded to the diameter of the vessel. In its expanded configuration, the stent supports and reinforces the vessel walls while maintaining the vessel in an open, unobstructed condition.

Both self-expanding and inflation expandable stents are well known and widely available in a variety of designs and configurations. Self-expanding stents must be maintained under positive external pressure in order to maintain their reduced diameter configuration during delivery of the stent to its deployment site. Inflation expandable stents may be crimped to their reduced diameter about the delivery catheter, maneuvered to the deployment site, and expanded to the vessel diameter by fluid inflation of a balloon positioned on the delivery catheter. The present invention is particularly concerned with delivery and deployment of inflation expandable stents, although it is generally applicable to self-expanding stents when used with balloon catheters.

In advancing an inflation expandable stent through a body vessel to the deployment site, there are a number of important considerations. The stent must be able to securely maintain its axial position on the delivery catheter, without translocating proximally or distally, and especially without becoming separated from the catheter. The stent, particularly its distal and proximal ends, must be protected to prevent distortion of the stent and to prevent abrasion and/or reduce trauma of the vessel walls.

Inflation expandable stent delivery and deployment assemblies are known which utilize restraining means that overlie the stent during delivery. U.S. Pat. No. 4,950,227 to Savin et al,relates to an expandable stent delivery system in which a sleeve overlaps the distal or proximal margin (or both) of the stent during delivery. That patent discloses a stent delivery system in which a catheter carries, on its distal end portion, a stent which is held in place around the catheter prior to and during percutaneous delivery by means of one and preferably two sleeves. The sleeves are positioned around the catheter with one end portion attached thereto and overlap an end portion(s) of the stent to hold it in place on the catheter in a contracted condition. Each sleeve is elastomeric in nature so as to stretch and release the stent when it expands for implantation. The stent is expandable by means of the expandable balloon on the catheter. During expansion of the stent at the deployment site, the stent margins are freed of the protective sleeve(s). U.S. Pat. No. 5,403,341 to Solar, relates to a stent delivery and deployment assembly which uses retaining sheaths positioned about opposite ends of the compressed stent. The retaining sheaths of Solar are adapted to tear under pressure as the stent is radially expanded, thus releasing the stent from engagement with the sheaths. U.S. Pat. No. 5,108,416 to Ryan et al., describes a stent introducer system which uses one or two flexible end caps and an annular socket surrounding the balloon to position the stent during introduction to the deployment site.

Copending U.S. patent application Ser. No. 09/407,836 which was filed on Sep. 28, 1999 and entitledStent Securement Sleeves and Optional Coatings and Methods of Use, and which is incorporated in its entirety herein by reference, also provides for a stent delivery system having sleeves. In 09/407,836 the sleeves may be made up of a combination of polytetrafluoroethylene (hereinafter PTFE) as well as one or more thermoplastic elastomers. Other references exist which disclose a variety of stent retaining sleeves.

The entire content of all patents and applications listed within the present patent application are incorporated herein by reference.

BRIEF SUMMARY OF THE INVENTION

This invention provides for one or more low profile double walled stent retaining sleeves which may be readily and fully retracted from a stent during stent delivery. The rolling retractable sleeves of the present invention improve over the prior art by providing a unique sleeve(s) which is designed to completely retract off of the stent during the stent delivery procedure. The present sleeve(s) are double-walled providing the sleeve(s) with the ability to roll and/or are otherwise retracted off of the stent ends by moving, such as by rolling, away from the stent mounting region or balloon along the catheter shaft. The ability of a sleeve to rollingly retract off of the stent allows the sleeve to retain its general shape and low profile throughout the stent delivery procedure.

In at least one embodiment of the invention the inside surfaces of the walls of the double walled sleeve may be lubricious in nature, have a lubricious coating thereon, or define a space which may contain a lubricant. The double walled structure of the sleeves allows each sleeve to be rollingly retracted completely off of a stent during stent delivery and avoids an accordion or wrinkled sleeve profile subsequent to stent delivery. The sleeves may be comprised of a combination of materials to provide the sleeves with a variety of characteristics such as those described in detail below.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

A detailed description of the invention is hereafter described with specific reference being made to the drawings in which:

FIG. 1 is a side view of an embodiment of the invention;

FIG. 2 is a side view of another embodiment of the invention;

FIG. 3 is a side view of another embodiment of the invention;

FIG. 4 is a side view of another embodiment of the invention;

FIG. 5 is a side view of the embodiment shown in FIG. 4, shown subsequent to stent delivery;

FIG. 6 is a side view of another embodiment of the invention;

FIG. 7 is a side view of the embodiment shown in FIG. 6 wherein the protective sheath has been retracted;

FIG. 8 is a side view of another embodiment of the invention;

FIG. 9 is a side view of the embodiment shown in FIG. 8 wherein the protective sheath has been retracted;

FIG. 10 is a side view of another embodiment of the invention;

FIG. 11 is a side view of another embodiment of the invention; and

FIG. 12 is a side view of another embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

As previously discussed, the present invention is directed to one or more double walled stent retaining sleeves. In FIG. I a pair of stent retaining sleeves, indicated generally at10, are shown. Theindividual sleeves10, are composed of a tubular doublewalled member12. The doublewalled member12 may be characterized as having a aninside layer14 and anoutside layer16, wherein theinside layer14 and theoutside layer16 are bonded together to be continuous with one another. The doublewalled member12 is formed by folding or everting one of the layers, such as theinside layer14, back upon itself to form the other layer, such asoutside layer16.

The doublewalled member12 when utilized with thestent delivery system30, such as may be seen in the embodiments shown in FIGS. 3-9, provides such thesystem30 withstent retaining sleeves10 which may be retracted completely off of thestent32 during a stent delivery procedure. As may best be seen in FIG. 5, in at least one of the embodiments discussed herein, the double walled construction of thesleeves10 provides the sleeves with the ability to roll off of the balloon orstent mounting region34 of thecatheter36 during stent delivery.

Thesleeves10 may be constructed to rollingly retract when subjected to a predetermined outwardly acting force. In the case of a self-expanding stent, such as may be seen in FIGS. 6-9, when thesheath33 is retracted off of thestent32 by pulling thesheath33 proximally via a pull backmember35, thestent32 will exert an outwardly acting radial force against thesleeves10. As may be seen in FIGS. 7 and 9, the force supplied by thestent32 will cause the sleeve(s)10 to retract off of the stent.

In the embodiment shown in FIGS. 8 and 9 asingle sleeve10 is used to overlay only one end of thestent32. As with any embodiment of the present invention, thesleeve10 may be configured to have a wide variety of lengths so as to provide for a variable extent of stent coverage. Thesleeve10 may even extend over the length of theentire stent32. However, in the embodiment shown, thesleeve10 overlays thedistal stent end48 while thesheath33 overlays theproximal end50. When thesheath33 is retracted via the pull backmember35 theproximal end50 is released resulting in a momentary flaring of theproximal end50 as the it begins to expand. As theproximal end50 expands thesleeve10 will retract off of thedistal end48 thereby allowing thedistal end48 to expand with theproximal end50.

In the embodiments shown in FIGS. 6-9 thestent mounting region34 may be an unexpanding portion of thecatheter36 or it may be expandable as previously discussed.

In an embodiment where thesleeves10 are utilized with a balloonexpandable stent32, such as may be seen in the embodiments shown in FIGS. 3-5, the force supplied by the expandingballoon34 which causes thestent32 to expand, will likewise trigger the retraction of thesleeves10 off of thestent32. In the case of a balloon expandable stent, the force exerted by theballoon34 will typically be 6 atmospheres or less.

Depending on several variables including: the materials used to make the sleeves, the materials used to make the catheter/balloon, and the type of engagement between the catheter and each sleeve; the sleeve(s)10 may be configured to retract off of thestent32 in a variety of manners.

Theballoon34 may be constructed of compliant materials, noncompliant materials or a combination thereof. Theballoon34 may be composed of compliant materials which include low pressure, relatively soft or flexible polymeric materials, such as thermoplastic polymers, thermoplastic elastomers, polyethylene (high density, low density, intermediate density, linear low density), various co-polymers and blends of polyethylene, ionomers, polyesters, polyurethanes, polycarbonates, polyamides, poly-vinyl chloride, acrylonitrile-butadiene-styrene copolymers, polyether-polyester copolymers, and polyetherpolyamide copolymers. Other suitable materials include a copolymer polyolefin material available from E.I. DuPont de Nemours and Co. (Wilmington, Del.), under the trade name SURLYN™ Ionomer and a polyether block amide available under the trade name PEBAX™. Non-compliant materials include relatively rigid of stiff high pressure polymeric materials, such as thermoplastic polymers and thermoset polymeric materials, poly(ethylene terephthalate) (commonly referred to as PET), polyimide, thermoplastic polyimide, polyamides, polyesters, polycarbonates, polyphenylene sulfides, polypropylene and rigid polyurethanes.

Depending on the composition of theballoon34 and the resulting extent of the frictional engagement between theballoon34 and thesleeve10, thesleeves10 may be configured to roll, slide, “snap” off, or otherwise retract in any manner or combination of manners such as is know in the art. An additional benefit provided for by thesleeves10 of the present invention, is that thesleeves10 may be fully retracted from thestent32 without “bunching up” or taking on an accordion-like configuration, which many prior sleeves are known to do. Thepresent sleeves10 may be provided with the ability to fully retract off of thestent32 as well as thestent mounting region34 while retaining the same sleeve profile throughout all phases of a stent delivery procedure.

In the present invention, thesleeves10 are constructed such that astent engagement end22 of the doublewalled member12 will tend to roll away from thestent32 andstent mounting region34, along thecatheter shaft38. As may be seen in FIG. 5, in at least one embodiment of the invention, the sleeves are capable of rolling along thecatheter shaft38, while retaining their general shape and profile, to fully retract off of thestent32. In order to assure thatsleeves10 roll away from and off of thestent32, a portion or end20 of theinside layer14 is constructed and arranged to engage a portion of acatheter shaft38. In the various embodiments invention, thesleeve10 may be utilized on acatheter36, thecatheter engagement end20 may be engaged to ashaft38 in a number of ways including but not limited to: frictional engagement; bonding, such as through the application of an adhesive; welding, such as heat, laser, and/or chemical welding.

In at least one embodiment of the invention, the sleeves my be configured to rollingly retract only partially off of thestent mounting region34, or to rollingly retract varying distances from thestent32 and/orstent mounting region34 as may be desired by the user.

As may be seen in FIGS. 1 and 3, the sleeves of the present invention may be configured to have little or no space between theinside layer14 and theoutside layer16. In the present embodiment, thelayers14 and16 havesurfaces24 and26 which are immediately adjacent to one another. One or bothsurfaces24 and26, or one or more portions thereof, may be lubricious or have alubricious coating28 thereon.

Alternatively, in the various embodiments shown in FIGS. 2 and 4, thesurfaces24 and26 may define a sealed space orchamber25. Theclosed space25 may be occupied in whole or in part by alubricious material29. Thelubricious material29 may be any material such as a fluid or a fluid like material which provides a reduced frictional engagement between thesurfaces24 and26. The lubricious material or coating may be, but is not limited to, the following materials: silicones; PVP (polyvinyl pyrrolidone); PPO (polypropylene oxide); PEO; oils, such as mineral oil, olive oil, vegetable oil, or other natural oils; wax; BioSlide™, a biocompatable coating produced by SciMed (BioSlide™ is a hydrophilic, lubricious coating comprising polyethylene oxide and neopentyl glycol diacrylate polymerized in a solution of water and isopropyl alcohol in the presence of a photoinitiator such as azobisisobutronitrile); and any combination thereof.

In the embodiments shown in FIGS. 1 and 3, The need and/or effectiveness of alubricious coating28 may be dependant on the characteristics of the material used to construct thelayers14 and16 and the interaction of thesurfaces24 and26. As previously discussed, other factors may implicate the need and/or type of lubricant used, such as the interface between thecatheter34 and thesleeve10. Thelayers14 an16 ofsleeve10 are typically manufactured from one or more thermoplastic elastomers, but may include additional and/or other materials as well. Some examples of suitable materials from which thelayers14 and16 may be constructed include, but are not limited to: SURLYN™, PEBAX™ and urethane, polypropylene, low density polyethylene (LDPE), high density polyethylene (HDPE), ethylene vinyl acetate (EVA), nylon, polyester and polyethylene terephthalate (“PET”), and any combination thereof.

In addition to having a wide range of suitable materials which thesleeves10 and thelayers14 and16 thereof may be made from, the sleeves may include additional surface features. In FIG. 11 an embodiment of the invention is shown which incorporates holes44. Theholes44 may be any of a variety of shapes and/or sizes and may be arranged either selectively or uniformly about the sleeve. Holes such as those utilized in the present embodiment are previously disclosed in U.S. patent application Ser. No. 09/549286, entitledStent Securement System, filed Apr. 14, 2000, the entire content of which is incorporated herein by reference. Thesleeves10 may also include surface texture on any surface of the sleeve. In FIG. 12 an embodiment is shown which incorporatesribs46. Thesleeve10 may be uniformly or selectively ribbed on any or all surfaces of the sleeve. A ribbed configuration is previously disclosed in U.S. patent application Ser. No. 09/552807, entitled ANon-Crimped Stent Delivery System, filed Apr. 20, 2000, the entire content of which is incorporated herein by reference.

Thelayers14 and16 may be constructed from the same or different materials. It may be desirable to provide asleeve10 which has a layer, be it theinside layer14 or theoutside layer16 or a portion thereof, which has different characteristics than the other layer or portions. For example, for purposes of providing asleeve10 with increased columnar strength so as to better secure a stent in place prior to stent delivery, it may be desirable to construct one of the layers (14 or16) or a portion thereof with a material which has more rigidity or greater hardness (as measured by the Shore scale) than the other layer which is less hard so as to promote flexibility. As indicated, the present invention also envisions sleeves which have only a portion or portions, such as thestent engagement end22 and/or thecatheter engagement end20, having various and different material compositions. It should also be noted thatend22 may include a lubricious surface or coating as discussed herein.

Where thelayers14 and16 are composed of a variety of materials, the materials which make up thelayers14 and16 may be bonded together by any means known.

Of particular concern to the present invention is the use of a lap weld to join the sleeve layers14 and16 together. A lap welded sleeve such as may be seen in FIG. 10, will providesleeve10 with a thickenedportion40. The thickenedportion40 provides thesleeve10 with a natural fold or break point which will tend to draw thesleeve10 away from thestent32 during expansion, and which will also provide thesleeve32 with a point upon which thesleeve10 will tend to fold over upon itself, should the sleeve fail to roll away from thestent32. Such folding action in prior sleeve designs is well known to those of skill in the art. Though the use of a lap weld is envisioned as a means to bond differentcompositional layers14 and16 together, the use of a thickenedportion40 may be used in any of the embodiments discussed herein. The addition of a thickened portion may be provided by lap welding layers14 and16 together. Alternatively, thesleeve10 may be originally manufactured, such as by extrusion with such a thickenedportion40 included.

In any of the embodiments discussed herein, a lubricious coating may be applied to any and all of the surfaces of thesleeve10. The use of a lubricious material orcoating28 as previously discussed, may be avoided if thesurfaces24 and26 have a frictional engagement such that the surfaces may readily slide against one another. If thesurfaces24 and26 are chemically attracted to one another or tend to engage or otherwise interfere with the movement of one another as thesleeve10 rolls, then the sleeve will not function properly. If it is not desired to lubricate thesurfaces24 and26, the surfaces, or a portion or portions thereof, may be treated so that they behave in a lubricious manner. To make thesurfaces24 and26 more lubricious, the surfaces or a portion or portions thereof may be treated to encourage cross-linking of the material from which thelayers14 and16, and thus surfaces24 and26 are constructed from. Such cross-linking may be achieved by exposing thesurfaces24 and26 to a plasma or charged ion field prior to mounting the sleeves on to thecatheter36.

The present invention is also directed to the use of other methods of encouraging or creating a lubricious surface on any of thelayers14 and16, surfaces24 and26, and/or ends20 and22 as discussed above, which may be known in the art.

In addition to being directed to the embodiments described above and claimed below, the present invention is further directed to embodiments having different combinations of the features described above and claimed below. As such, the invention is also directed to other embodiments having any other possible combination of the dependent features claimed below.

The above examples and disclosure are intended to be illustrative and not exhaustive. These examples and description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the attached claims. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims attached hereto.

Claims (40)

What is claimed is:

1. A stent delivery system comprising:

a stent delivery catheter, the stent delivery catheter having a stent retaining region;

a stent disposed about at least a portion of the stent retaining region, the stent having an unexpanded state and being expandable to an expanded state;

at least one stent retaining sleeve, the at least one sleeve having a tubular double walled construction comprising a first layer and a second layer, a lubricant between the first layer and the second layer, a first portion of the first layer engaging at least a portion of the stent delivery catheter, a second portion of the first layer overlying an end of the stent when the stent is in the unexpanded state, the at least one stent retaining sleeve constructed and arranged to rollingly retract off of the stent when the stent is expanded to the expanded state, whereby during expansion of the stent the at least one sleeve retracts off of the stent.

2. The stent delivery system ofclaim 1, comprising a pair of sleeves.

3. The stent delivery system ofclaim 2, the first layer comprising an inside surface and the second layer comprising an inside surface.

4. The stent delivery system ofclaim 3, wherein at least a portion of the inside surface of the first layer is in sliding contact with at least a portion of the inside surface of the second layer.

5. The stent delivery system ofclaim 4 wherein the at least a portion of the inside surface of the first layer and the at least a portion of the inside surface of the second layer material are composed substantially of cross-linked materials.

6. The stent delivery system ofclaim 5, wherein the cross-linked materials are produced by exposing the at least a portion of the inside surfaces of the first and second layers to a plasma field.

7. The stent delivery system ofclaim 3, wherein the inside surface of the first layer and the inside surface of the second layer define a closed space therebetween.

8. The stent delivery system ofclaim 7, wherein the closed space is at least partially filled with the lubricant.

9. The stent delivery system ofclaim 8, wherein the lubricant is selected from the group consisting of: silicones, polyvinyl pyrrolidone, polypropylene oxide, mineral oil, olive oil, vegetable oil, wax, compounds of polyethylene oxide and neopentyl glycol diacrylate polymerized in a solution of water and isopropyl alcohol in the presence of a photoinitiator, and any combination thereof.

10. The stent delivery system ofclaim 1, wherein the first layer is composed of a first material and the second layer is composed of a second material.

11. The stent delivery system ofclaim 10, wherein the first material is different from the second material.

12. The stent delivery system ofclaim 10, wherein the first material and the second material are each selected from the group consisting of: copolyrner polyolefin, Ionomer and a polyether block amide, urethanes, polypropylene, low density polyethylene, high density polyethylene, ethylene vinyl acetate, nylon, polyester and polyethylene terephthalate, polyurethane, and any combination thereof.

13. The stent delivery system ofclaim 10, wherein the first layer is lap welded to the second layer.

14. The stent delivery system ofclaim 10, wherein the first layer and the second layer further comprise a thickened portion.

15. The stent delivery system ofclaim 11, wherein the second material has different Shore D hardness than the first material.

16. The stent delivery system ofclaim 1, wherein the stent delivery catheter further comprises a catheter shaft, the catheter shaft being adjacent to the stent retaining region, the first portion of the first layer being fixedly engaged to at least a portion of the catheter shaft.

17. The stent delivery system ofclaim 16, wherein the first portion of the first layer being welded to the at least a portion of the catheter shaft.

18. The stent delivery system ofclaim 16, wherein the first portion of the first layer being laser welded to the at least a portion of the catheter shaft.

19. The stent delivery system ofclaim 16, wherein the first portion of the first layer being adhesively bonded to the at least a portion of the catheter shaft.

20. The stent delivery system ofclaim 1, wherein the second portion of the first layer is lubricious.

21. The stent delivery system ofclaim 1 wherein the second portion of the first layer has a lubricious coating thereon.

22. The stent delivery system ofclaim 1, further comprising a retractable sheath, the retractable sheath having a proximally extending pull back member, the retractable sheath at least partially overlapping the stent prior to stent delivery.

23. The stent delivery system ofclaim 22, wherein the stent is a self-expanding stent.

24. The stent delivery system ofclaim 23, the retractable sheath overlapping a proximal portion of the stent prior to stent delivery.

25. The stent delivery system ofclaim 23, the at least one stent retaining sleeve overlapping at least a distal portion of the stent prior to stent delivery.

26. The stent delivery system ofclaim 2, further comprising a retractable sheath, the retractable sheath having a proximally extending pull back member, the retractable sheath overlapping the stent and the pair of stent retaining sleeves prior to stent delivery.

27. The stent delivery system ofclaim 1, the at least one stent retaining sleeve having at least one surface which is textured.

28. The stent delivery system ofclaim 27, wherein the at least one textured surface is ribbed.

29. The stent delivery system ofclaim 1, the first layer defining at least one hole therethrough.

30. The stent delivery system ofclaim 1, the second layer defining at least one hole therethrough.

31. The stent delivery system ofclaim 1, the first layer and the second each defining at least one hole therethrough.

32. The stent delivery system ofclaim 31, wherein the stent is balloon expandable.

33. The stent delivery system ofclaim 31, the stent retaining region comprising a stent delivery balloon.

34. The stent delivery system ofclaim 23, the stent retaining region comprising a stent delivery balloon.

35. A rolling retractable stent retaining sleeve for retaining a stent on a balloon catheter comprising:

a tubular double walled sleeve, the tubular double walled sleeve comprising a first layer and a second layer, a lubricant between the first layer of material and the second layer of material, a first portion of the first layer constructed and arranged to engage at least a portion of the balloon catheter, a second portion of the first layer constructed and arranged to overlay an end of the stent prior to stent delivery, the tubular double walled sleeve constructed and arranged to rollingly retract off of the stent when the stent exerts an outwardly acting radial pressure on the first portion, whereby during stent delivery the tubular double walled sleeve is fully retracted off of the stent.

36. The stent retaining sleeve ofclaim 35 wherein the sleeve further comprises a lubricant between the first layer of material and the second layer of material.

37. The stent retaining sleeve ofclaim 35 wherein the first layer and the second layer define a closed chamber.

38. The stent delivery system ofclaim 37 wherein the lubricant is contained in the closed chamber.

39. The stent delivery system ofclaim 35, at least a portion of the first portion having a lubricious coating thereon.

40. A method of delivering a stent comprising the steps of:

providing a stent delivery catheter wherein the stent delivery catheter includes characterized as having:

an inflatable region,

an expandable stent disposed about the inflatable region, the stent having an unexpanded state and an expanded state,

and at least one tubular double walled sleeve, the at least one tubular double walled sleeve comprising a first layer and a second layer, a lubricant between the first layer of material and the second layer of material, a first portion of the first layer constructed and arranged to engage at least a portion of the catheter, a second portion of the first layer constructed and arranged to overlay an end of the stent prior to stent delivery, the at least one tubular double walled sleeve constructed and arranged to rollingly retract off of the stent when the stent is expanded to the expanded state, whereby during stent delivery the at least one tubular double walled sleeve is fully retracted off of the stent;

inserting the stent delivery catheter into a body vessel;

advancing the balloon catheter to a predetermined delivery location;

inflating the inflatable portion thereby expanding the stent from the unexpanded state to the expanded state and

rollingly retracting the at least one sleeve off of the at least a portion of the stent thereby exposing the stent for delivery; and

retracting the stent delivery catheter from the body vessel.

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